Allen Smith ran for student-body president in the fourth grade. He'd just transferred from private school and barely knew most of the kids in his class.

And when the new kid won the election, the principal told Smith's mother, Elsie Moore, that her son seemed destined for a career in politics.

Moore, truth be told, had something else in mind. She was a university professor - as was Smith's late father. She envisioned her son following her footsteps into academia.

Now a senior at Stanford, Smith might yet end up in politics or in a lecture hall - but not before he takes a shot as his dream of playing in the NFL.

It was a dream in serious jeopardy not too long ago, but the Cardinal offensive tackle from Arizona has been working, healing and hoping for an opportunity to get it back. He finally might be there.

After sustaining a serious knee injury early in the 2007 season, Smith - widely considered a pro prospect at that point - endured months of rehab and another significant setback, and then faced the possibility that he would not play football again.

"The thought that I might not be able to play with my guys again truly weighed on my mind," Smith said. "But the one thing I can never do is doubt myself. So while I might have been worried, my passion for the game kept me going."

As Stanford finishes its first week of spring practice, Smith is back in the fold, ready to return to the field and resume the pursuit of his NFL ambition.

Stanford head coach Jim Harbaugh is cautiously optimistic about Smith's return to the active roster. He anticipates Smith will be ready to play in the spring game April 13.

"He'll be available. He needs to get ramped up into full-contact, full-scrimmage-type drills," Harbaugh said. "How long that will take remains to be seen. We need to push the envelope without getting Allen hurt. He will be at some risk, but our doctors and our trainers and he all feel like he's going to give it a great go."

Smith would open the 2009 season as a sixth-year senior, granted an extra year of eligibility by the NCAA.

He has one more chance to get back to where he was in 2007, when on the third play of the third game, he ruptured the patellar tendon in his left knee, with 95 percent of the tendon torn from the bone.

"We didn't know much at first," Moore said. "I was in line getting ready to board my plane when he called me and told me he was having surgery and he wanted me to stay. I got out of line, got my rental car back and went back to Stanford."

Smith's rehab was going well in February 2008, when his left kneecap (patella) fractured while he was working on a leg-press machine. Again, he had surgery.

To say he was "concerned" about his future in football is putting a nice face on his fear.

"I was terrified," Smith said. "To say there's more to life than football, yeah, that's true. But not much. To have it taken away from me and not leave on my own terms, that was tough."

Moore said her youngest son's passion for football has been apparent since the first day he went to practice in high school. Moore refused to let him play before that, afraid he would get hurt. She was convinced he would come home after that first practice and complain that it was too hard, too hot in the desert sun.

"Instead, he came home and said he loved it," Moore said.

Smith said he feels like he's in the best physical condition of his life, having spent six days a week for the past 10 weeks strengthening his lower body in anticipation of practice.

Harbaugh said he believes Smith has the potential to return to NFL-prospect form.

He has been fitted with a custom brace that includes a protective plate over his kneecap.

"There's some rust there," Harbaugh said. "We've seen him in winter conditioning drills, and he's looked really good. You can see the explosiveness, the power in his hands, the punch, the ability to move, his athleticism and strength.

"Allen wouldn't be coming back for a sixth year if he didn't feel like he could do that, and we wouldn't be having him back if we didn't think he could get back to that."

Smith said his NFL ambitions were among his main motivations for coming back.

"I always had aspirations for playing at the highest level and I still hold those," Smith said. "I have never wanted to be mediocre, never in my whole life. A bad knee is not how I wanted my legacy at Stanford to end, gimping on the sideline, riding a bike. I want to be there for my last season."